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| United States Patent |
5,104,769
|
|
Looker
, et al.
|
April 14, 1992
|
High contrast photographic element and emulsion and process for their use
Abstract
Photographic elements and emulsions are described which are capable of
providing high contrast images. The elements and emulsions comprise
negative working silver halide and contrast enhancing arylhydrazide
nucleating agents. A process for utilization of the elements and emulsions
is also described.
| Inventors:
|
Looker; Jerome J. (Rochester, NY);
Leone; Ronald E. (Rochester, NY);
Fleckenstein; Lee J. (Rochester, NY)
|
| Assignee:
|
Eastman Kodak Company (Rochester, NY)
|
| Appl. No.:
|
167814 |
| Filed:
|
March 14, 1988 |
| Current U.S. Class: |
430/264; 430/598 |
| Intern'l Class: |
G03C 001/34 |
| Field of Search: |
430/598,264
|
References Cited
U.S. Patent Documents
| 4323643 | Apr., 1982 | Mifune et al. | 430/441.
|
| 4332878 | May., 1982 | Akimura et al. | 430/264.
|
| 4975354 | Dec., 1990 | Machonkin et al. | 430/264.
|
| Foreign Patent Documents |
| 196626 | Oct., 1986 | EP.
| |
| 0286840 | Mar., 1988 | EP.
| |
| 3610273 | Oct., 1986 | DE.
| |
Primary Examiner: Bowers, Jr.; Charles L.
Assistant Examiner: Baxter; Janet C.
Attorney, Agent or Firm: Janci; David F.
Claims
What is claimed is:
1. A photographic recording material capable of providing a high contrast
silver image which comprises a support having thereon a negative-working
silver halide emulsion layer and a hydrazide compound having one of the
following structural formulae:
##STR25##
wherein; R is alkyl having from about 8 to about 16 carbon atoms or a
heterocyclic ring having 5 or 6 ring atoms, including ring atoms of sulfur
or oxygen;
R.sup.1 is alkyl or alkoxy having from 1 to about 12 carbon atoms;
X is alkyl, thioalkyl or alkoxy having from 1 to about 5 carbon atoms;
halogen; or --NHCOR.sup.2, --NHSO.sub.2 R.sup.2, --CONR.sup.2 R.sup.3 or
--SO.sub.2 R.sup.2 R.sup.3 where R.sup.2 and R.sup.3, which can be the
same or different, are hydrogen or alkyl having from 1 to about 4 carbon
atoms; and
n is 0, 1 or 2.
2. The photographic recording material of claim 1 wherein R.sup.1 is alkyl
or alkoxy of from 1 to about 5 carbon atoms.
3. The photographic recording material of claim 1 wherein R is a thienyl or
a furyl group.
4. The photographic recording material of claim 1 wherein the hydrazide
compound has the structural formula:
##STR26##
5. The photographic recording material of claim 1 wherein the hydrazide
compound has the structural formula:
##STR27##
6. The photographic recording material of claim 1 wherein the hydrazide
compound has the structural formula:
##STR28##
7. The photographic recording material of claim 1 wherein the hydrazide
compound has the structural formula:
##STR29##
8. The photographic recording material of claim 1 wherein the hydrazide
compound has the structural formula:
##STR30##
9. The photographic recording material of claim 1 wherein the hydrazide
compound has the structural formula:
##STR31##
10. The photographic recording material of claim 1 wherein the hydrazide
compound has the structural formula:
##STR32##
11. A photographic emulsion comprising negative working silver halide and a
hydrazide nucleating compound having one of the following structural
formulae:
##STR33##
wherein; R is alkyl having from about 8 to about 16 carbon atoms or a
heterocyclic ring having 5 or 6 ring atoms, including ring atoms of sulfur
or oxygen;
R.sup.1 is alkyl or alkoxy having from 1 to about 12 carbon atoms;
X is alkyl, thioalkyl or alkoxy having from 1 to about 5 carbon atoms; or
halogen; or --NHCOR.sup.2, --NHSO.sub.2 R.sup.2, --CONR.sup.2 R.sup.3 or
--SO.sub.2 R.sup.2 R.sup.3 where R.sup.2 and R.sup.3, which can be the
same or different, are hydrogen or alkyl having from 1 to about 4 carbon
atoms; and
n is 0, 1 or 2.
12. The photographic emulsion of claim 11 wherein R.sup.1 is alkyl or
alkoxy of from 1 to about 5 carbon atoms.
13. The photographic emulsion of claim 11 wherein R is a thienyl or a furyl
group.
14. The photographic emulsion of claim 11 wherein the hydrazide compound
has the structural formula:
##STR34##
15. The photographic emulsion of claim 11 wherein the hydrazide compound
has the structural formula:
##STR35##
16. The photographic emulsion of claim 11 wherein the hydrazide compound
has the structural formula:
##STR36##
17. The photographic emulsion of claim 11 wherein the hydrazide compound
has the structural formula:
##STR37##
18. The photographic emulsion of claim 11 wherein the hydrazide compound
has the structural formula:
##STR38##
19. The photographic emulsion of claim 11 wherein the hydrazide compound
has the structural formula:
##STR39##
20. The photographic emulsion of claim 11 wherein the hydrazide compound
has the structural formula:
##STR40##
21. A process for forming a high contrast photographic image which
comprises exposing and developing a photographic recording material
comprising a negative-working silver halide emulsion layer and a hydrazide
nucleating compound having one of the following structural formulae:
##STR41##
wherein; R is alkyl having from about 8 to about 16 carbon atoms or a
heterocyclic ring having 5 or 6 ring atoms, including ring atoms of sulfur
or oxygen;
R.sup.1 is alkyl or alkoxy having from 1 to about 12 carbon atoms;
X is alkyl, thioalkyl or alkoxy having from 1 to about 5 carbon atoms;
halogen; or --NHCOR.sup.2, --NHSO.sub.2 R.sup.2, --CONR.sup.2 R.sup.3 or
--SO.sub.2 R.sup.2 R.sup.3 where R.sup.2 and R.sup.3, which can be the
same or different, are hydrogen or alkyl having from 1 to about 4 carbon
atoms; and
n is 0, 1 or 2 by use of a hydroquinone developing agent.
Description
This invention relates to a high contrast photographic element and emulsion
and to a process for obtaining a high contrast photographic image
therefrom.
High contrast negative photographic images useful in the graphic arts and
printing industries are generally obtained by developing a `lith` type
emulsion (usually high in silver chloride content) in a hydroquinone, low
sulphite, developer solution. It has been recognized that addition of
nucleating agents to "lith" type emulsions can provide further
improvements in contrast of resulting negative images.
Nucleating agents which have been effective and which have found wide
commercial acceptance are hydrazide compounds, particularly
formylhydrazide compounds. Many compounds of this type have been proposed
for incorporation in high contrast silver halide materials.
U.S. Pat. No. 4,323,643 describes various formylhydrazide nucleating agents
and their use in photographic elements for obtaining high contrast
negative images having improved dot quality and dot gradation while
employing reduced pH developer compositions. The pH of the developer
solutions is stated to be above about 9 and preferably from about 9.5 to
10.8. Included among these agents are 1-substituted ureidophenyl-2-formyl
hydrazides which are developed in the presence of a dihydroxybenzene
compound. However, the contrast values obtained with such substituted
ureido hydrazide compounds are not fully acceptable. This is illustrated
below by tests showing that hydrazide compounds described in the '643
patent do not provide contrast values of the type which can be obtained
with the hydrazide compounds of the present invention.
European Patent Application 196,626 also describes photographic materials
useful for obtaining high contrast negative images using various hydrazide
nucleating agents. These agents include a benzene sulfonamidophenyl
hydrazide as well as alkyl substituted phenoxybutyramidohydrazide
compounds. However, as is also demonstrated below by comparative data,
such nucleating agents do not provide contrast values such as can be
obtained with the hydrazide compounds disclosed in this invention.
Results from use of known nucleating agents have not provided sufficiently
high contrast levels while simultaneously preserving other features which
are desired in high contrast photographic images.
Accordingly, there is a continuing need for nucleating agents for high
contrast photographic elements which are useful at operating conditions
below a pH level of 11 without sacrificing desirable contrast properties
in the final images.
The present invention is based upon a photographic element capable of
providing a high contrast silver image which comprises a support having
thereon a negative-working silver halide emulsion layer and a hydrazide
nucleating compound having one of the following structural formulae:
##STR1##
wherein; R is alkyl having from 6 to about 18 carbon atoms or a
heterocyclic ring having 5 or 6 ring atoms, including ring atoms of sulfur
or oxygen;
R.sup.1 is alkyl or alkoxy having from 1 to about 12 carbon atoms;
X is alkyl, thioalkyl or alkoxy having from 1 to about 5 carbon atoms;
halogen; or --NHCOR.sup.2, --NHSO.sub.2 R.sup.2, --CONR.sup.2 R.sup.3 or
--SO.sub.2 R.sup.2 R.sup.3 where R.sup.2 and R.sup.3, which can be the
same or different, are hydrogen or alkyl having from 1 to about 4 carbon
atoms; and
n is 0, 1 or 2.
The present invention is also based on a photographic emulsion comprising
negative-working photosensitive silver halide and a hydrazide nucleating
compound having one of the following structural formulae:
##STR2##
wherein; R is alkyl having from 6 to about 18 carbon atoms or a
heterocyclic ring having 5 or 6 ring atoms, including ring atoms of sulfur
or oxygen;
R.sup.1 is alkyl or alkoxy having from 1 to 12 carbon atoms;
X is alkyl, thioalkyl or alkoxy having from 1 to about 5 carbon atoms;
halogen; or --NHCOR.sup.2, --NHSO.sub.2 R.sup.2, --CONR.sup.2 R.sup.3 or
--SO.sub.2 R.sup.2 R.sup.3 where R.sup.2 and R.sup.3, which can be the
same or different, are hydrogen or alkyl having from 1 to about 4 carbon
atoms; and
n is 0, 1 or 2.
Alkyl groups represented by R can be straight or branched chain and can be
substituted or unsubstituted. Substituents include alkoxy having from 1 to
about 4 carbon atoms, halogen atoms (e.g. chlorine and fluorine), or
--NHCOR.sup.2 or --NHSO.sub.2 R.sup.2 where R.sup.2 is as defined above.
Preferred R alkyl groups contain from about 8 to about 16 carbon atoms
since alkyl groups of this size impart a greater degree of insolubility to
the hydrazide nucleating agents and thereby reduce the tendency of these
agents to be leached during development from the layers in which they are
coated into developer solutions.
Heterocyclic groups represented by R include thienyl and furyl, which
groups can be substituted with alkyl having from 1 to about 4 carbon atoms
or with halogen atoms, such as chlorine.
Alkyl or alkoxy groups represented by R.sup.1 can be straight or branched
chain and can be substituted or unsubstituted. Substituents on these
groups can be alkoxy having from 1 to about 4 carbon atoms, halogen atoms
(e.g. chlorine or fluorine); or --NHCOR.sup.2 or --NHSO.sub.2 R.sup.2
where R.sup.2 is as defined above. Preferred alkyl or alkoxy groups
contain from 1 to 5 carbon atoms in order to impart sufficient
insolubility to the hydrazide nucleating agents to reduce their tendency
to being leached out of the layers in which they are coated by developer
solution.
Alkyl, thioalkyl and alkoxy groups which are represented by X contain from
1 to about 5 carbon atoms and can be straight or branched chain. When X is
halogen, it may be chlorine, fluorine, bromine or iodine. Where more than
1 X is present, such substituents can be the same or different.
Representative examples of hydrazide nucleating agents which are suitable
for use in this invention include:
__________________________________________________________________________
Compound No.
__________________________________________________________________________
1
##STR3##
2
##STR4##
3
##STR5##
4
##STR6##
5
##STR7##
6
##STR8##
7
##STR9##
8
##STR10##
9
##STR11##
10
##STR12##
11
##STR13##
12
##STR14##
13
##STR15##
14
##STR16##
15
##STR17##
16
##STR18##
17
##STR19##
18
##STR20##
__________________________________________________________________________
Hydrazide compounds described herein which are suitable for use in the
present invention can be prepared, for example, by reducing
1-formyl-2-(4-nitrophenyl)-hydrazide to the corresponding amine which is
then caused to react with an alkyl- or an aryl- sulfonyl halide compound
to form the desired sulfonamidophenyl hydrazide. This method is
illustrated below in preparation of an alkoxysulfonamidophenyl hydrazide
compound and a substituted arylsulfonamidophenyl hydrazide compound.
Synthesis of Compound 10
1-[(p-methoxybenzenesulfonamido)phenyl]-2-formyl-hydrazide
A solution of 5.40 grams (0.030 mole) of
1-formyl-2-(4-nitrophenyl)hydrazide in 200 ml of dry tetrahydrofuran was
reduced with hydrogen (276 kPa) in the presence of Pd on carbon catalyst
at room temperature over a period of one hour. The mixture was dried over
sodium sulfate and filtered. The filtrate was stirred and cooled to
0.degree. C.; then 3.9 grams (0.030 mole) of N,N-diisopropylethylamine was
added, followed by a solution of 6.2 grams (0.030 mole) of
4-methoxy-benzenesulfonyl chloride in 20 ml of tetrahydrofuran, added
dropwise. After 15 hours stirring at room temperature, the solution was
concentrated to a gum, which solidified on washing with water. The solid
was recrystallized from 300 ml of methanol to yield 6.0 g (62%) of
product, m.p. 194.degree.-195.degree. C. (dec).
Synthesis of Compound 3
1-(n-octylsulfonamidophenyl)-2-formylhydrazide
The procedure described above for Compound 10 was used, with the exception
that 6.42 g (0.03 mole) of n-octanesulfonyl chloride was used in place of
methoxybenzenesulfonyl chloride. The gum resulting from concentration of
the reaction mixture was chromatographed on silica gel, and the solid
product obtained was recrystallized from diethyl ether to yield 6.0 g
(61%) of Compound 3, m.p. 108.degree.-109.degree..
The hydrazide nucleating agents described herein can be present in the
photographic elements and emulsions of this invention in a concentration
of from about 10.sup.-4 to about 10.sup.-1 mol per mol of silver. A
preferred quantity of the hydrazide compound is from 5.times.10.sup.-4 to
about 5.times.10.sup.-2 mol per mol of silver. Optimum results are
obtained when the hydrazide compound is present in a concentration of from
about 8.times.10.sup.-4 to about 5.times.10.sup.-3 mol per mol of silver.
The hydrazide compound can be incorporated in a photographic silver halide
emulsion layer or, alternatively, the hydrazide compound can be present in
a hydrophilic colloid layer of the photographic element. Preferably, such
hydrophilic colloid layer is coated contiguous to the emulsion layer in
which the effects of the hydrazide compound are desired. The hydrazide
compound can also be present in the photographic element in other layers
such as subbing layers, interlayers or overcoating layers.
The present invention also provides a process for forming a high contrast
photographic image which comprises developing a photographic recording
material comprising a negative-working silver halide emulsion layer and a
hydrazide nucleating compound having one of the following structural
formulae:
##STR21##
wherein: R is alkyl having from 6 to about 18 carbon atoms or a
heterocyclic ring having 5 or 6 ring atoms, including ring atoms of sulfur
or oxygen;
R.sup.1 is alkyl or alkoxy having from 1 to about 12 carbon atoms;
X is alkyl, thioalkyl or alkoxy having from 1 to about 5 carbon atoms;
halogen; or --NHCOR.sup.2, --NHSO.sub.2 R.sup.2, --CONR.sup.2 R.sup.3 or
--SO.sub.2 R.sup.2 R.sup.3 where R.sup.2 and R.sup.3, which can be the
same or different, are hydrogen or alkyl having from 1 to about 4 carbon
atoms; and
n is 0, 1 or 2 by use of a hydroquinone developing agent.
The above-described process can be operated at pH levels below about 11
without sacrificing the advantages obtained with the improved hydrazide
nucleating agents.
The hydrazide compounds are employed in combination with negative-working
photographic emulsions comprised of radiation-sensitive silver halide
grains capable of forming a surface latent image and a binder. The silver
halide emulsions include high chloride emulsions conventionally employed
in forming lithographic photographic elements, as well as silver bromide
and silver bromoiodide emulsions which are recognized in the art as being
capable of attaining higher photographic speeds. Generally, the iodide
content of the silver halide emulsions is less than about 10 mole percent
silver iodide, based on total silver halide.
Silver halide grains suitable for use in the emulsions of this invention
are capable of forming a surface latent image, as opposed to being of the
internal latent image-forming type. Surface latent image silver halide
grains are employed in the majority of negative-working silver halide
emulsions, whereas internal latent image-forming silver halide grains,
while capable of forming a negative image when developed in an internal
developer, are usually employed with surface developers to form
direct-positive images. The distinction between surface latent image and
internal latent image silver halide grains is generally well recognized in
the art.
Although the difference between a negative image produced by a surface
latent image emulsion and a positive image produced by an internal latent
image emulsion when processed in a surface developer is a qualitative
difference which is visually apparent to even the unskilled observer, a
number of tests have been devised to distinguish quantitatively surface
latent image-forming from internal latent image-forming emulsions. For
example, according to one such test when the sensitivity resulting from
surface developer (A), described below, is greater than that resulting
from internal developer (B), described below, the emulsion being
previously light exposed for a period of from 1 to 0.01 second, the
emulsion is of a type which is "capable of forming a surface latent image"
or, more succinctly, it is a surface latent image emulsion. The
sensitivity is defined by the following equation:
##EQU1##
in which S represents the sensitivity and Eh represents the quantity of
exposure necessary to obtain a mean density, i.e., 1/2 (D.sub.max
+D.sub.min).
SURFACE DEVELOPER (A)
The emulsion is processed at 20.degree. C. for 10 minutes in a developer
solution of the following composition:
______________________________________
N-methyl- -p-aminophenol (hemisulfate)
2.5 g
Ascorbic acid 10 g
Sodium metaborate.4H.sub.2 O
35 g
Potassium bromide 1 g
Water to 1 liter
______________________________________
INTERNAL DEVELOPER (B)
The emulsion is processed at about 20.degree. C. for 10 minutes in a
bleaching solution containing 3 g of potassium ferricyanide per liter and
washed with water for 10 minutes and developed at 20.degree. C. for 10
minutes in a developer solution having the following composition:
______________________________________
N-methyl- -p-aminophenol (hemisulfate)
2.5 g
Ascorbic acid 10 g
Sodium metaborate.4H.sub.2 O
35 g
Potassium bromide 1 g
Sodium thiosulfate 3 g
Water to 1 liter
______________________________________
The silver halide grains, when the emulsions are used for lith
applications, have a mean grain size of not larger than about 0.7 micron,
preferably about 0.4 micron or less. Mean grain size is well understood by
those skilled in the art, and is illustrated by Mees and James, The Theory
of the Photographic Process, 3rd Ed., MacMillan 1966, Chapter 1, pp.
36-43. The photographic emulsions can be coated to provide emulsion layers
in the photographic elements of any conventional silver coverage.
Conventional silver coverages fall within the range of from about 0.5 to
about 10 grams per square meter.
As is generally recognized in the art, higher contrasts can be achieved by
employing relatively monodispersed emulsions. Monodispersed emulsions are
characterized by a large proportion of the silver halide grains falling
within a relatively narrow size-frequency distribution. In quantitative
terms, monodispersed emulsions have been defined as those in which 90
percent by weight or by number of the silver halide grains are within plus
or minus 40 percent of the mean grain size.
Silver halide emulsions contain, in addition to silver halide grains, a
binder. The proportion of binder can be widely varied, but typically is
within the range of from about 20 to 250 grams per mol of silver halide.
Excessive binder can have the effect of reducing maximum densities and
consequently also reducing contrast. For contrast values of 10 or more it
is preferred that the binder be present in a concentration of 250 grams
per mol of silver halide, or less.
The binders of the emulsions can be comprised of hydrophilic colloids.
Suitable hydrophilic materials include both naturally occurring substances
such as proteins, protein derivatives, cellulose derivatives, e.g.,
cellulose esters, gelatin, e.g., alkali-treated gelatin (pigskin gelatin),
gelatin derivatives, e.g., acetylated gelatin, phthalated gelatin and the
like, polysaccharides such as dextran, gum arabic, zein, casein, pectin,
collagen derivatives, collodion, agar-agar, arrowroot, albumin and the
like as described in U.S. Pat. Nos. 2,614,928; 2,614,929; 2,614,930;
2,691,582; 2,327,808; 2,448,534; 2,787,545; 2,956,880; 3,061,436;
2,816,027; 3,132,945; 3,138,461; 3,186,846; 2,960,405; 3,436,220;
3,486,896; 2,992,213; 3,157,506; 3,184,312; 3,539,353; 3,227,571;
3,532,502; 3,551,151; 3,923,517; 4,018,609; 2,110,491; 2,311,086;
2,343,650; 2,322,085; 2,563,791; 2,725,293; 2,748,022; 2,956,883; and U.K.
Patent Nos. 793,549; 1,167,159; 1,186,790; 1,483,551 and 1,490,644 which
patent disclosures are incorporated herein by reference.
In addition to hydrophilic colloids the emulsion binder can be optionally
comprised of synthetic polymeric materials which are water insoluble or
only slightly soluble, such as polymeric latices. These materials can act
as supplemental grain peptizers and carriers, and they can also
advantageously impart increased dimensional stability to the photographic
elements. The synthetic polymeric materials can be present in a weight
ratio with the hydrophilic colloids of up to 2:1. It is generally
preferred that the synthetic polymer materials constitute from about 20 to
80 percent by weight of the binder.
Suitable synthetic polymer materials can be chosen from among poly(vinyl
lactams), acrylamide polymers, polyvinyl alcohol and its derivatives,
polyvinyl acetals, polymers of alkyl and sulfoalkyl acrylates and
methacrylates, hydrolyzed polyvinyl acetates, polyamides, polyvinyl
pyridine, acrylic acid polymers, maleic anhydride copolymers, polyalkylene
oxides, methacrylamide copolymers, polyvinyl oxazolidinones, maleic acid
copolymers, vinylamine copolymers, methacrylic acid copolymers,
acryloyloxyalkylsulfonic acid copolymers, sulfoalkylacrylamide copolymers,
polyalkyleneimine copolymers, polyamines, N,N-dialkylaminoalkyl acrylates,
vinyl imidazole copolymers, vinyl sulfide copolymers, vinyl sulfide
copolymers, halogenated styrene polymers, amineacrylamide polymers,
polypeptides and the like as described in U.S. Pat. Nos. 3,679,425;
3,706,564; 3,813,251; 2,253,078; 2,276,322; 2,276,323; 2,281,703;
2,311,058; 2,414,207; 2,484,456; 2,541,474; 2,632,704; 3,425,836;
3,415,653; 3,615,624; 3,488,708; 3,392,025; 3,511,818; 3,681,079;
3,721,565; 3,852,073; 3,861,918; 3,925,083; 3,879,205; 3,142,568;
3,062,674; 3,220,844; 2,882,161; 2,579,016; 2,829,053; 2,698,240;
3,003,879; 3,419,397; 3,284,207; 3,167,430; 2,957,767; 2,893,867;
2,869,986; 2,904,539; 3,929,482; 3,860,428; 3,939,130; 3,411,911;
3,287,289; 2,211,323; 2,284,877; 2,420,455; 2,533,166; 2,495,918;
2,289,775; 2,565,418; 2,865,893; 2,875,059; 3,536,491; 3,479,186;
3,520,857; 3,690,888; and 3,748,143, and U.K. Patent Nos. 808,227;
808,228; 822,192; 1,062,116; 1,398,055 and 1,466,600, which patent
disclosures are incorporated herein by reference.
Although the term "binder" is employed in describing the continuous phase
of the silver halide emulsions, it is recognized that other terms commonly
employed by those skilled in the art, such as carrier or vehicle, can be
interchangeably employed. The binders described in connection with the
emulsions are also useful in forming undercoating layers, interlayers and
overcoating layers of the photographic elements of this invention.
Typically the binders are hardened with one or more photographic
hardeners, such as those described in Paragraph VII, Product Licensing
Index, Vol. 92, December 1971, Item 9232, which disclosure is hereby
incorporated by reference.
Emulsions according to this invention having silver halide grains of any
conventional geometric form (e.g., regular cubic or octahedral crystalline
form) can be prepared by a variety of techniques, e.g., single-jet,
double-jet (including continuous removal techniques), accelerated flow
rate and interrupted precipitation techniques, as illustrated by Trivelli
and Smith, The Photographic Journal, Vol. LXXIX, May, 1939, pp. 330-338,
T. H. James, The Theory of the Photographic Process, 4th Ed., Macmillan,
1977, Chapter 3, Terwilliger et al Research Disclosure, Vol. 149,
September 1976, Item 14987, as well as U.S. Pat. Nos. 2,222,264;
3,650,757; 3,672,900; 3,917,485; 3,790,387; 3,761,276 and 3,979,213, and
German OLS No. 2,107,118 and U.K. Patent Publications 335,925; 1,430,465
and 1,469,480, which publications are incorporated herein by reference.
Double jet accelerated flow rate precipitation techniques are preferred for
forming monodispersed emulsions. Sensitizing compounds, such as compounds
of copper, thallium, cadmium, rhodium, tungsten, thorium, iridium and
mixtures thereof, can be present during precipitation of the silver halide
emulsion, as illustrated by U.S. Pat. Nos. 1,195,432; 1,951,933;
2,628,167; 2,950,972; 3,488,709; and 3,737,313, all incorporated herein by
reference.
The individual reactants can be added to the reaction vessel through
surface or sub-surface delivery tubes by gravity feed or by delivery
apparatus for maintaining control of the pH and/or pAg of the reaction
vessel contents, as illustrated by U.S. Pat. Nos. 3,821,002 and 3,031,304
and Claes et al, Photographische Korrespondenz, 102 Band, Number 10, 1967,
p. 162. In order to obtain rapid distribution of the reactants within the
reaction vessel, specially constructed mixing devices can be employed, as
illustrated by U.S. Pat. Nos. 2,996,287; 3,342,605; 3,415,650; and
3,785,777; and German OLS Nos. 2,556,885 and 2,555,364. An enclosed
reaction vessel can be employed to receive and to mix reactants upstream
of the main reaction vessel, as illustrated by U.S. Pat. Nos. 3,897,935
and 3,790,386.
The grain size distribution of the silver halide emulsions can be
controlled by silver halide grain separation techniques or by blending
silver halide emulsions of differing grain sizes. The emulsions can
include ammonical emulsions, as illustrated by Glafkides, Photographic
Chemistry, Vol. 1, Fountain Press, London, 1958, pp. 365-368 and pp.
301-304; thiocyanate ripened emulsions, as illustrated by U.S. Pat. No.
3,320,069; thioether ripened emulsions, as illustrated by U.S. Pat. Nos.
3,271,157; 3,574,628 and 3,737,313 or emulsions containing weak silver
halide solvents, such as ammonium salts, as illustrated by U.S. Pat. No.
3,784,381 and Research Disclosure, Vol. 134, June 1975, Item 13452.
The silver halide emulsion can be unwashed or washed to remove soluble
salts. The soluble salts can be removed by chill setting and leaching, as
illustrated by U.S. Pat. Nos. 2,316,845 and 3,396,027; by coagulation
washing, as illustrated by U.S. Pat. Nos. 2,618,556; 2,614,928; 2,565,418;
3,241,969 and 2,489,341 and by U.K. Patent Nos. 1,035,409 and 1,167,159;
by centrifugation and decantation of a coagulated emulsion, as illustrated
by U.S. Pat. Nos. 2,463,794; 3,707,378; 2,996,287 and 3,498,454; by
employing hydrocyclones alone or in combination with centrifuges, as
illustrated by U.K. Patent Nos. 336,692 and 1,356,573; by diafiltration
with a semipermeable membrane, as illustrated by Research Disclosure, Vol.
102, October 1972, Item 10208. The emulsions, with or without sensitizers,
can be dried and stored prior to use as illustrated by Research
Disclosure, Vol. 101, September 1972, Item 10152.
The silver halide emulsions can be chemically sensitized with active
gelatin, as illustrated by T. H. James, The Theory of the Photographic
Process, 4th Ed., Macmillan, 1977, pp. 67-76, or with sulfur, selenium,
tellurium, platinum, palladium, iridium, osmium, rhenium or phosphorus
sensitizers or combinations of these sensitizers, such as at pAg levels of
from 5 to 10, pH levels of from 5 to 8 and temperatures of from 30.degree.
to 80.degree. C., as illustrated by Research Disclosure, Vol. 134, June
1975, Item 13452. The emulsions need not be chemically sensitized,
however, in order to exhibit the advantages of this invention.
The silver halide emulsions can be spectrally sensitized with dyes from a
variety of classes, including the polymethine dye class, which includes
the cyanines, merocyanines, complex cyanines and merocyanines (i.e., tri-,
tetra- and polynuclear cyanines and merocyanines), oxonols, hemioxonols,
styryls, merostyryls and streptocyanines.
By suitable choice of substituent groups the dyes can be cationic, anionic
or nonionic. Preferred dyes are cationic cyanine and merocyanine dyes.
Emulsions containing cyanine and merocyanine dyes have been observed to
exhibit relatively high contrasts. Spectral sensitizing dyes specifically
preferred for use in the practice of this invention are as follows:
SS-1: Anhydro-5,5'-dichloro-9-ethyl-3,3'-bis(3-sulfopropyl)oxacarbocyanine
hydroxide, sodium salt
SS-2: 5,5',6,6'-Tetrachloro-1,1',3,3'-tetraethylbenzimidazolocarbocyanine
iodide
SS-3: 3,3'-Diethyl-9-methylthiacarbocyanine bromide
SS-4: 3,3'-Diethyloxacarbocyanine iodide
SS-5: 5,5'-Dichloro-3,3',9-triethylthiacarbocyanine bromide
SS-6: 3,3'-Diethylthiocarbocyanine iodide
SS-7: 5,5'-Dichloro-2,2'-diethylthiocarbocyanine, p-toluene sulfonate salt
SS-8:
3-Carboxymethyl-5-[(3-methyl-2-thiazolidinylidene)-1-methylethylidene]rhod
anine
SS-9: 3-Ethyl-3-[3-ethyl-2-thiazolidinylidene)-1-methylethylidene]rhodanine
SS-10
5-[(3-(2-Carboxyethyl)-2-thiazolidinylidene)ethylidene]-3-ethylrhodanine
SS-11
1-Carboxymethyl-5-[(3-ethyl-2-benzothiazolinylidene)ethylidene]-3-phenyl-2
-thiohydantoin
SS-12
1-Carboxymethyl-5-[(1-ethyl-2(H)-naphtho[1,2-d]thiazolin-2-ylidene)ethylid
ene]-3-phenyl-2-thiohydantoin
SS-13:
3-Carboxymethyl-5-[(3-ethyl-2-benzothiazolinylidene)ethylidene]rhodanine
SS-14:
5-[(3-Ethyl-2-benzoxazolinylidene)ethylidene]-3-heptyl-2-thio-2,4-oxazolid
inedione
SS-15: 3-Carboxymethyl-5-(3-ethyl-2-benzothiazolinylidene)rhodanine
SS-16: 3-Carboxymethyl-5-(3-methyl-2-benzoxazolinylidene)rhodanine
SS-17: 3-Ethyl-5-[(3-ethyl-2-benzoxazolinylidene)ethylidene]rhodanine.
The photographic elements can be protected against fog by incorporation of
antifoggants and stabilizers in the element itself or in the developer in
which the element is to be processed. Illustrative of conventional
antifoggants and stabilizers useful for this purpose are those disclosed
by Paragraph V, Product Licensing Index, Vol. 92, December 1971, Item
9232, which publication is hereby incorporated by reference.
It has been observed that both fog reduction and an increase in contrast
can be obtained by employing benzotriazole antifoggants either in the
photographic element or the developer in which the element is processed.
The benzotriazole can be located in the emulsion layer or in any other
hydrophillic colloid layer of the photographic element in a concentration
in the range of from 10.sup.-4 to 10.sup.-1, preferably 10.sup.-3 to
3.times.10.sup.-2, mol per mol of silver. When the benzotriazole
antifoggant is added to the developer, it is employed in a concentration
of from 10.sup.-6 to about 10.sup.-1, preferably 3.times.10.sup.-5 to
3.times.10.sup.-2, mol per liter of developer.
Useful benzotriazoles can be chosen from among conventional benzotriazole
antifoggants. These include benzotriazole (that is, the unsubstituted
benzotriazole compound), halo-substituted benzotriazoles (e.g.,
5-chlorobenzotriazole, 4-bromobenzotriazole and 4-chlorobenzotriazole) and
alkyl-substituted benzotriazoles wherein the alkyl moiety contains from 1
to about 12 carbon atoms (e.g., 5-methylbenzotriazole).
In addition to the components of the photographic emulsions and other
hydrophilic colloid layers described above it is appreciated that other
conventional element addenda compatible with obtaining relatively high
contrast images can be present. For example, addenda can be present in the
described photographic elements and emulsions in order to stabilize
sensitivity. Preferred addenda of this type include carboxyalkyl
substituted 3H-thiazoline-2-thione compounds of the type described in U.S.
Pat. No. 4,634,661. Also the photographic elements can contain developing
agents (described below in connection with the processing steps),
development modifiers, plasticizers and lubricants, coating aids,
antistatic materials, matting agents, brighteners and color materials,
these conventional materials being illustrated in Paragraphs IV, VI, IX,
XII, XIII, XIV and XXII of Product Licensing Index, Vol. 92, December
1971, Item 9232, incorporated herein by reference.
The hydrazide compounds, sensitizing dyes and other addenda incorporated
into layers of the photographic elements can be dissolved and added prior
to coating either from water or organic solvent solutions, depending upon
the solubility of the addenda. Ultrasound can be employed to dissolve
addenda. Semipermeable and ion exchange membranes can be used to introduce
addenda, such as water soluble ions (e.g., chemical sensitizers).
Hydrophobic addenda, particularly those which need not be adsorbed to the
silver halide grain surfaces to be effective, such as couplers, redox
dye-releasers and the like, can be mechanically dispersed directly or in
high boiling (coupler) solvents, as illustrated in U.S. Pat. Nos.
2,322,027 and 2,801,171, or the hydrophobic addenda can be loaded into
latices and dispersed, as illustrated by Research Disclosure, Vol. 159,
July 1977, Item 15930.
In forming photographic elements the layers can be coated on photographic
supports by various procedures, including immersion or dip coating, roller
coating, reverse roll coating, doctor blade coating, gravure coating,
spray coating, extrusion coating, bead coating, stretch-flow coating and
curtain coating. High speed coating using a pressure differential is
illustrated by U.S. Pat. No. 2,681,294.
The layers of the photographic elements can be coated on a variety of
supports. Typical photographic supports include polymeric film, wood
fiber, e.g., paper, metallic sheet or foil, glass and ceramic supporting
elements provided with one or more subbing layers to enhance the adhesive,
antistatic, dimensional, abrasive, hardness, frictional, antihalation
and/or other properties of the support surface.
Typical of useful polymeric film supports are films of cellulose nitrate
and cellulose esters such as cellulose triacetate and diacetate,
polystyrene, polyamides, homo- and co-polymers of vinyl chloride,
poly(vinyl acetal), polycarbonate, homo- and copolymers of olefins, such
as polyethylene and polypropylene, and polyesters of dibasic aromatic
carboxylic acids with divalent alcohols, such as poly(ethylene
terephthalate).
Typical of useful paper supports are those which are partially acetylated
or coated with baryta and/or a polyolefin, particularly a polymer of an
.alpha.-olefin containing 2 to 10 carbon atoms, such as polyethylene,
polypropylene, copolymers of ethylene and propylene and the like.
Polyolefins, such as polyethylene, polypropylene and polyallomers, e.g.,
copolymers of ethylene with propylene, as illustrated by U.S. Pat. No.
4,478,128, are preferably employed as resin coatings over paper, as
illustrated by U.S. Pat. Nos. 3,411,908 and 3,630,740, over polystyrene
and polyester film supports, as illustrated by U.S. Pat. No. 3,630,742, or
can be employed as unitary flexible reflection supports, as illustrated by
U.S. Pat. No. 3,973,963.
Preferred cellulose ester supports are cellulose triacetate supports, as
illustrated by U.S. Pat. Nos. 2,492,977; 2,492,978 and 2,739,069, as well
as mixed cellulose ester supports, such as cellulose acetate propionate
and cellulose acetate butyrate, as illustrated by U.S. Pat. No. 2,739,070.
Preferred polyester film supports are comprised of linear polyester, such
as illustrated by U.S. Pat. Nos. 2,627,088; 2,720,503; 2,779,684 and
2,901,466.
The photographic elements can be imagewise exposed with various forms of
energy, which encompass the ultraviolet and visible (e.g., actinic) and
infrared regions of the electromagnetic spectrum as well as electron beam
and beta radiation, gamma ray, X-ray, alpha particle, neutron radiation
and other forms of corpuscular and wavelike radiant energy in either
noncoherent (random phase) forms or coherent (in phase) forms, as produced
by lasers. Exposures can be monochromatic, orthochromatic or panchromatic.
Imagewise exposures at ambient, elevated or reduced temperatures and/or
pressures, including high or low intensity exposures, continuous or
intermittent exposures, exposure times ranging from minutes to relatively
short durations in the millisecond to microsecond range and solarizing
exposures, can be employed within the useful response ranges determined by
conventional sensitometric techniques, as illustrated by T. H. James, The
Theory of the Photographic Process, 4th Ed., Macmillan, 1977, Chapters 4,
6, 17, 18 and 23.
The light-sensitive silver halide contained in the photographic elements
can be processed following exposure to form a visible image by associating
the silver halide with an aqueous alkaline medium in the presence of a
developing agent contained in the medium or the element. It is a distinct
advantage of the present invention that the described photographic
elements can be processed in conventional developers as opposed to
specialized developers conventionally employed in conjunction with
lithographic photographic elements to obtain very high contrast images.
When the photographic elements contain incorporated developing agents, the
elements can be processed in the presence of an activator, which can be
identical to the developer in composition, but otherwise lacking a
developing agent. Very high contrast images can be obtained at pH values
in the range of from 11 to 12.3, but preferably lower pH values, for
example below 11 and most preferably in the range of about 9 to about 10.8
are preferably employed with the photographic recording materials as
described herein.
The developers are typically aqueous solutions, although organic solvents,
such as diethylene glycol, can also be included to facilitate the solvency
of organic components. The developers contain one or a combination of
conventional developing agents, such as a polyhydroxybenzene, aminophenol,
para-phenylenediamine, ascorbic acid, pyrazolidone, pyrazolone,
pyrimidine, dithionite, hydroxylamine or other conventional developing
agents. It is preferred to employ hydroquinone and 3-pyrazolidone
developing agents in combination. The pH of the developers can be adjusted
with alkali metal hydroxides and carbonates, borax and other basic salts.
To reduce gelatin swelling during development, compounds such as sodium
sulfate can be incorporated into the developer. Also, compounds such as
sodium thiocyanate can be present to reduce granularity. Chelating and
sequestering agents, such as ethylenediaminetetraacetic acid or its sodium
salt, can be present. Generally, any conventional developer composition
can be employed in the practice of this invention. Specific illustrative
photographic developers are disclosed in the Handbook of Chemistry and
Physics, 36th Edition, under the title "Photographic Formulae" at page
3001 et seq. and in Processing Chemicals and Formulas, 6th Edition,
published by Eastman Kodak Company (1963), the disclosures of which are
here incorporated by reference. The photographic elements can, of course,
be processed with conventional developers for lithographic photographic
elements, as illustrated by U.S. Pat. No. 3,573,914 and U.K. Patent No.
376,600.
Product Licensing Index and Research Disclosure are published by Kenneth
Mason Publications, Ltd., The Old Harbourmaster's, 8 North Street,
Emsworth, Hampshire P010 7DD, ENGLAND.
The invention is further described by the examples illustrated below.
Each coating used in the following examples was prepared on a polyester
support, using a monodispersed 0.25 .mu.m AgBrI (3 mol % iodide) emulsion
at 3.47 g/m.sup.2 Ag, 2.24 g gel/m.sup.2, and 0.96 g latex/m.sup.2 where
the latex is a copolymer of methyl acrylate,
2-acrylamido-2-methylpropane-sulfonic acid, and methacrylamide (88:5:7
monomer weight ratio). The silver halide emulsion was spectrally
sensitized with 216 mg/Ag mol of
anhydro-5,5'-dichloro-9-ethyl-3,3'-di-(3-sulfopropyl) oxacarbocyanine
hydroxide, triethylamine salt. The nucleating agents were added as
methanol solutions to the emulsion melts at a level of 2.0.times.10.sup.-3
mol/Ag mole. The emulsion layer was overcoated with gelatin containing
polymethylmethacrylate beads.
EXAMPLE 1
Coatings 1, 2, 3, 4 and 5 were exposed for 1 second to a 3000.degree. K.
tungsten light source and processed for 2 minutes at 35.degree. C. in the
following developer solution:
______________________________________
KOH, 45% 12.4 g
K.sub.2 SO.sub.3, 45% 25 g
NaBr 3.0 g
Hydroquinone 15.0 g
Na.sub.2 CO.sub.3 10.0 g
Ethylenediaminetetraacetic acid
2.1 g
NaOH, 50% 2.3 g
3-(Diethylamino)-1,2-propanediol
29.4 g
1-Phenyl-4,4-dimethyl-3-pyrazolidone
0.20 g
1-Phenyl-5-mercaptotetrazole
0.076 g
Phenethylpicolinium bromide
2.8 g
5-Methylbenzotriazole 0.10 g
Nitrilomethylenephosphoric acid,
0.35 g
pentasodium salt, 40%
Water to 1 liter
______________________________________
pH was measured as 10.9.
Results are recorded in Table I.
TABLE I
______________________________________
Coating Nucleator
No. Compound No. DMax EC (i) USC (ii)
______________________________________
1 Comparison (a)
4.14 6.45 2.36
2 Comparison (b)
5.20 13.3 5.83
3 6 5.04 15.5 18.2
4 7 5.20 31.3 21.5
5 10 4.90 20.3 20.1
______________________________________
Comparison (a):
##STR22##
which is Compound I9 of European Patent Application 196,626.
Comparison (b):
##STR23##
which is Compound I29 of European Patent Application 196,626.
(i) EC is a measurement of effective contrast which represents the averag
slope between density values of 0.1 and 2.50.
(ii) USC is a measurement of upper scale contrast which represents the
average slope between density values of 2.50 and 4.00.
Overall improvements in contrast values obtained from the compounds of this
invention, as compared with the prior art compounds, are readily observed
from Table I.
EXAMPLE 2
Coatings 6, 7, 8 and 9 were exposed as described in Example 1. Processing
was for a 1-minute period at 35.degree. C. using the developer solution of
Example 1 modified in that it contained only 20% of the level of
phenethylpicolinium bromide (i.e. 0.56 gram per liter), as used in Example
1. Results are reported in Table II.
TABLE II
______________________________________
Coating Nucleator
No. Compound No.
DMax EC* USC*
______________________________________
6 Comparison (c)
4.67 7.65 6.05
7 3 4.82 21.1 13.1
8 10 4.67 14.0 1.83
9 9 4.96 28.3 8.22
______________________________________
Comparison (c):
##STR24##
which compound falls within the disclosure of U.S. Pat. No. 4,323,643.
*As described above for Table I.
Table II reflects advantages of compounds of this invention over the ureido
substituted hydrazide compound of the prior art. Improved maximum density
and/or contrast values, particularly effective contrast, are readily
apparent from the table.
EXAMPLE 3
Coatings of the type used in Example 2 were exposed as described in Example
1 and processed for 2 minutes at 35.degree. C. in the following developer
solution:
______________________________________
KOH, 45% 35.6 g
NaOH, 50% 9.2 g
Sodium metabisulfite 29 g
Wetting Agent 2.6 g
Diethylethylenetriamino-
3.0 g
pentaacetate, penta
sodium salt, 40%
NaBr 2.4 g
Hydroquinone 13 g
1-Phenyl-4-hydroxymethyl-4-
0.58 g
methyl-3 pyrazolidone
Benzotriazole 0.08 g
1-Phenyl-5-mercaptotetrazole
0.01 g
Boric Acid 1.39 g
Diethylene glycol 24 g
K.sub.2 CO.sub.3, 47% 24 g
3-(Diethylamino)-1,2-pro-
29.4 g
panediol
Water to 1 liter
pH was measured to 10.7
______________________________________
Results are recorded in Table III.
TABLE III
______________________________________
Coating
No. Compound No.
DMax EC* USC*
______________________________________
6 Comparison (c)
5.27 8.69 5.91
7 3 5.48 20.9 33.1
8 10 4.94 9.01 8.72
9 9 5.37 19.5 18.3
______________________________________
*As described above in Table I.
Comparison (c) is as described above in Table II.
Table III reflects continued improved contrast values for compounds of this
invention with respect to the described prior art compound.
EXAMPLE 4
Coatings of the type described in Example 2 were exposed as in Example 1
and processed for one minute at 35.degree. C. in developer solution. The
developer was similar to that used in Example 3 except that it also
contained 0.56 g of phenethylpicolinium bromide.
Results are recorded in Table IV.
TABLE IV
______________________________________
Coating
No. Compound No.
DMax EC* USC*
______________________________________
6 Comparison (c)
5.22 10.6 3.24
7 3 5.13 16.6 4.21
8 10 4.70 16.6 1.67
9 9 5.14 19.9 17.4
______________________________________
*As described above in Table I.
Comparison (c) is as described above in Table II.
From the data in Table IV it can be seen that the hydrazide nucleating
agents of this invention yield improved contrast values, particularly
effective contrast, when compared with the known prior art compound.
The invention has been described in detail with reference to preferred
embodiments thereof but it will be understood that variations and
modifications can be effected within the spirit and scope of the
invention.
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